Twist drill depth gauge



Aug- 2, 1949- o. B. oNl-:ILL l2,477,891

TWIST DRILL DEPTH GAUGE Filed Dec. 5, 1945.

Fig. 3.

. Inventor Urville B. O'Nell By A Patented ug. 2, I1949 UISJITED STATES PATENT OFFICE.

TWIST DRILL DEPTH GAUGE Orville B.A ONeill, Duncan, British Columbia., Canada, assignor of fty per cent to Joseph E. ONeill,` Vernon, British Columbia, Canada Application December 5, 1946, Serial No. 714,313

2 Claims.

This invention relates ful improvements in tool attachments and accessories and has reference in particular to a device which is expressly, but not necessarily, adapted to be mounted on a standard-type twist drill, the purpose of the device being to function as a drill stop, this in a manner to limit the penetration of the drill into the work and to thus promote accurate drilling and counter-boring operations.

An object of the invention is to provide a simple and expedient combination drill stop and depth gauge which is easy to attach and detach and which will not score or scratch the surface of the work, generally steel, even though said surface be comparatively soft.

Another object of the invention is to provide an effective and practical double purpose drill attachment which serves as acombination stop andgauge, the same having a work contacting head whose peripheral portion is beveled to afford clear visibility of the hole being bored, said head being further constructed with ways and means whereby the accumulating borings and chips are permitted to escape and twirl free of the -head in a manner to promote clear view working conditions.

An outstanding object of the invention is to provide an attachment of the aforementioned type which permits a tool maker or other artisan to carry on counter-sinking and counter-boring operations to a degree of requisite precision in proper depth relation to either a hand drill or a drill press, thus making it possible to secure accurate work from assistants and helpers who could not, under ordinary circumstances, be depended upon to achieve skillful and reliable accomplishments.

A further object of the invention is to'provide an attachment characterized by reliable means permitting same to be secured adjustably to the shank of a twist drill, said means being such that the upper end-of the stop means may be swivelly mounted in place, the lower end of said means being characterized by the aforementioned head, the features lending themselves appreciably well directed in order to respond to present day drilling techniques, making it possible to speed up and economize` on production, insuring continua ing accuracy.

Other objects, features and advantages will become more readily apparent` from the following description and the accompanying illustrative drawings. Y

In the drawings, wherein like numerals are employed to designate like parts throughout the Views:

` Figure 1 is a view in section and elevation showing a fragmentary portion of the steel or equivalent block being bored and showing the to certain new and useattachment mounted on the twist drill, the attachment being in section;

Figure 2 is a view similar to Figure 1, but showing half portions of the work and attachment in elevation, said gure also showing a modified adjustable head construction;

Figure 3 is a bottom plan view which may be said to be taken approximately on the plane of the line 3-3 of Figure 1, looking in the direction of the arrows; and,

Figure 4 is a cross section on the plane of the line 4--4 of Figure 2, also looking in the direction of the arrows.

Reference is had rst to Figure 1 vwherein the work piece of steel or equivalent material is denoted by the reference character A, the surface thereof B having been drilled by a standard-type twist-drill C to provide a counter-bore or equivalent socket D. Incidentally, the shank of the drill is denoted at E and is adapted to be clamped in a hand-drill or chuck in a drill press (not shown).

The invention at bar comprises an attaching and clamping sleeve 6 of appropriate internal and external diameters to achieve the ends sought, said sleeve being adjustably secured to the shank of the drill by set-screws or the like 8. The sleeve is provided with a shoulder forming ange 9 and below this with an extended end portion I0 which is slightly reduced in diameter and which may be referred to as an assembling bushing. Surrounding the bushing and abutting the shoulder 9 is a bearing in the form of a suitable ball race structure II. The bearing is fitted into a cup-like member I2 on the upper end of the stop I3. In fact, the upper edge of the rim of the cup is peened or otherwise formed as at Ill to provide a retention lip and to thus assemble the clamping sleeve and stop means I3. It will be noted also that the bushing-end extends into the bore I5 of said stop means I3, the bore being considerably larger than the outside diameter of the drill C. A collar I6 is tightly `fitted into the lower end portion of the stop, said collar permitting passage of the drill through and beyond same and being provided at its outer end with an enlarged head I1 abutting the lower end of the body I3, the outer marginal edge portion of the head being beveled, for purposes of visibility, as at I8. The surface I9 is a machined surface, accurately flattened and finished to provide an abutment engageable with the work-piece A. The numerals 20 merely designate circumferentially spaced notches or pockets for accumulation and automatic clearance of the grindings and chips.

In using the attachment, the same is clamped in place on the twist-drill as shown in Figure 1 and the drill is set and clamped in the chuck of a hand-drill or a drill-press as the case may be. It is desirable, in this connection, that the jaws of the chuck rest against the upper end of the clamping sleeve 6 so as to assist in preventing slippage vof the sleeve once the set-screws 8 are tightened. It is obvious, that since-the sleeve is fastened to the tool it will rotate therewith and with the chuck. The sleeve and bearing carried thereby is stopped when once the headed end of the stop body I3 comes into engagement or contact with the work-piece surface B, this in an obvious manner. Then, the desired free turning and swivelling action is permitted, the drilling having then been stopped.

In the modied form of the invention disclosed in Figures 2 and 4, the work-piece is denoted by the reference character A', the surface thereo f being B'. The twist-drill is denoted by the reference character C' and the socket is at D'. Furthermore, the shank of the drill is denoted at E.

The clamping sleeve 6a is assembled and held in place on the shank of the drillbyset-screws 8a, the stop shoulder or flange being denoted at 81a and the assembling bushing or extension being at 10a. The roller Vbearingrneans lis at Ila and the cylindrical shallow cup 12a on the upper end of the st-op body or means I3a. receives the bearing and has a retention lip Ma holding the bearing in place and assembling the parts 6a and |3a in relatively rotatable relationship. The parts so far described are the same as seen in the form of the invention depicted in Figure l which accounts for the general correspondence in reference characters and exponents used in connection therewith. The new features are as follows:

The body of the stop means Ia is here designated by 'the reference numeral 2i and is flat based to provide a suitable wrench or tool-grip. It vis provided at its lower end with a tapered nipple-like extension 2la having internal and external screw threads 22 and 23, The extension is also provided with longitudinal slots circumferentially spaced and defining collet-like gripping jaws. These jaws embrace and grip the threaded surface of the collar 24, said collar having a head 25 formed with' a tool-grip and said head being tapered as at 26. This provides an abutment surface 2l engageable with the work-piece and appropriate notches 28 are provided for clearance of metallic chips and borings. A lc-ck nut 2S is provided and this is tapered and threaded on the tapered external surfaces of the collet-like jaws or grips.

The operation in this form of the invention is generally the saine as that previously described, except 'that the adjustment means provides f or a finer regulation. It is possible to make principal adjustment by shifting and locating the sleeve 6c on the shank and then tightening the set-screws 8a. After the main adjustment is made by taking a rough measurement between the tip of the drill and the abutment surface 2l, said surface 21 can be adjusted either in or out by properly loosening the lock nut and adjusting the collar in the jawlilke grips. nut 29 is tightened to maintain said adjustment.

t is believed that the attaclnncnt is possessed of outstanding and readily recognizable and identifiable structural and functional characteristics, TheA volume of chips is 4released and cleared out, handily. The parts. are hardened for propel' impact. properties. and the device as a whore insures speeding up and economizing production resu1ts. Assured and continuous ac- Once the adjustment is vhad the lock 4. curacy and uniform end thrust pressure results is also a feature not to be overlooked.

A careful consideration of the foregoing description in conjunction with 'the invention as illustrated in the drawings will enable the reader to obtain a clear understanding and impression of the alleged features of merit and novelty sufricient to clarify the construction of the invention 'as hereinafter claimed.

Minor changes in shape, size, materials and rearrangement of parts may be resorted to in actual practice so long as no departure is made from the invention as claimed.

I claim:

1. In a twist drill depth gauge of the class described, an 'elongated sleeve `adapted to be adjustably mounted on a drill shank, a body swivelly mounted on said sleeve, said body having an external wrench `gripping portion, an extension projecting beyond said portion, said extension being tapered, circumferentially and longitudinally slotted, and internally and externally screw-threaded to provide collet-like gripping jaws, a screw-threaded collar screwed into said jaws and having a work contactinghead provided with chips clearance notches and a marginally bevelled surface, and a lock nut surrounding said jaws and -engageable with said head.

2. A twist drill depth gauge of the class shown `and described comprising `an elongated sleeve adapted to be adjustably mounted on the shank of a drill, said sleeve being provided intermediate its ends with an outstanding flange providing a shoulder, an end portion of the sleeve beyond said shoulder being formed into an assembling bushing, a body formed at one end with a bearing containing cup, said cupped end surrounding said bushing adjacent said flange, anti-friction bearing means in said cup and held partly in place by the cup and partly in place by the flange and serving to provide a swivel connection between the bod'y and sleeve, said body including a flat-faced tool grip and being formed beyond said grip with an extension, said extension being tapered, circumferentially and longitudinally slotted, and internally and externally screw threaded to provide collet-like gripping jaws, a screw threaded collar screwed in said jaws and having at its outer end a work contacting head provided with clearance notches for borings and chips, the marginal portion of said head having wrench gripping surfaces, and a lock nut mounted on and surrounding said jaws and engageable with said head.

ORVILLE B. ONEILL.

REFERENCES CITED The following references are of record in the le of 'this patent:

UNITED STATES PATENTS Number Name Date 303,303 Mansfield Aug. l2, 1884 554,443 Henry Feb. 1l, 1896 739,946 Straub Sept. 29, 1903 2,898,055 Cogsdill Jan. 12, 1943 2,380,330 Rinzler July 10, 12945 2,40%,652 King Oct, l, 1946 FOREIGN PATENTS Number Country Date 188,356 Germany Nov. 25, 1906 510,482 Great'Brtain Aug. 2, 1939 

